Զարուհի Կարաբեկյան

Լաբորատորիայի վարիչՊրոֆեսոր, կ.գ.թ.

Regeneration of skin and neural tissue is one of the biggest requirements of modern days. Transplantation of autologous cells to repair a damaged organ is the ultimate goal of cell-based regenerative medicine. However, the availability of such cells in sufficient amounts and within a short time frame following injury is a major problem. Because non-autologous donor cells are likely to induce an immune response, the use of allogeneic or xenogeneic cell grafts typically requires nonspecific systemic immunosuppression of the host. There are 2 alternative options to address this problem: first is to create donor stem cells which do not elicit immune response, yet are capable of differentiating into a desired cell type. However if the donor antigens responsible for stimulation an immune response are down-regulated then rejection should diminish. Derivation of donor cells from stem cells provides a unique opportunity to modify donor cells in such a way that they circumvent rejection by the host. As a result, the integrity of the graft will be better preserved and the recipient will require less immunosuppression.

To achieve this goal we propose a novel strategy of diminishing the expression of Major Histocompatibility Complex class I molecules (MHC I) on the surface of grafted cells in order to minimize their rejection by the host.

Second option is to generate a collection of stem cells of different haplotypes, which will be of-the-shelf solution for generation of immuno-compatible tissues of solid organs.

Goals

Toward this goal we propose to isolate and preserve mesenchymal stem cells from adipose tissue readily available following cosmetic surgeries. Armenian population is characterized by unique and ancient MHC haplotypes These genes are also common among many nations in Mediterranean and Middle East regions However there is an ongoing controversy about uniqueness of HLA haplotypes typical for population historically lived on Armenian Plateau. Studies demonstrate of a relatively large Armenian population sample group demonstrated a prevalent haplotype for HLA-A, HLA-B, and HLA-DRB alleles.

However, as a result of complex history among populations inhabiting this region, the gene pool of the Armenian population may contain traces of historically well-documented ancient migrations. Therefore considering the fact of modern globalization, people’s migration and largely unexplored genetic recourses of Armenian population, we propose to create and characterise a collection of mesenchymal stem cells in order to secure availability of immuno-compatible pluripotent cells. We are convinced that this repository will be in high demand based on the experience of our colloquies at the Armenian Bone Marrow Donor's Registry. This organization is one of the world's 65 bone marrow registries. The ABMDR receives daily requests for hematopoietic stem cells of certain haplotypes from all over the globe. However there is no such repository of the stem cells for solid organ regeneration.